A productive, veteran NHL center, Ribeiro first made his mark in the Quebec Major Junior Hockey League with Rouyn-Noranda. In 1997-98 he won the Michel Bergeron Trophy as the QMJHL's top rookie and the Paul Dumont Trophy as its personality of the year after leading the league in assists (85). He was named to the 1998 Canadian Hockey League All-Rookie Team and QMJHL Second All-Star Team and played in the 1998 CHL Top Prospects Game.
The Montreal Canadiens selected Ribeiro in the second round (No. 45) of the 1998 NHL Draft. In 1998-99 he was named a CHL First-Team All-Star and QMJHL First-Team All-Star after claiming the CHL Top Scorer Award and the Jean Beliveau Trophy for most points in the QMJHL with 167 (67 goals).